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CVE Record

CVE-2021-38512: An issue was discovered in the actix-http crate before 3.0.0-beta.9 for Rust.

An issue was discovered in the actix-http crate before 3.0.0-beta.9 for Rust. HTTP/1 request smuggling (aka HRS) can occur, potentially leading to credential disclosure.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-38512 affects the Rust actix-http crate before 3.0.0-beta.9. The issue can allow HTTP/1 request smuggling, which may let one user’s request interfere with another and potentially expose credentials. The source bundle does not provide CVSS, CWE, confirmed affected applications, or active exploitation evidence.

Executive priority

Treat this as a targeted dependency remediation item, not a broad emergency. The potential impact is credential disclosure, but the provided evidence lacks active exploitation, severity scoring, and product-level exposure detail.

Technical view

The vulnerability is in actix-http HTTP/1 request handling before 3.0.0-beta.9. The published description says HTTP request smuggling can occur, with possible credential disclosure. Available sources do not provide parser details, exploit prerequisites, CVSS scoring, or a CWE classification.

Likely exposure

Exposure is limited to Rust applications or packages using actix-http versions before 3.0.0-beta.9. The bundle does not identify specific downstream products beyond a Fedora package advisory, so asset owners must confirm dependency usage locally.

Exploitation context

CISA KEV is false, and the supplied sources do not state active exploitation. Public advisories describe the vulnerability class and potential impact, but not real-world exploitation, exploit maturity, or required deployment conditions.

Researcher notes

The key gap is technical detail: sources do not describe the exact HTTP/1 parsing condition, required topology, or exploit reliability. Validation should focus on dependency presence, deployed versions, and whether vulnerable actix-http code is reachable in HTTP/1 request paths.

Mitigation direction

  • Upgrade actix-http to 3.0.0-beta.9 or later where applicable.
  • Check RustSec and vendor advisories for supported fixed package versions.
  • Review Fedora advisory applicability for Fedora-managed systems.
  • Prioritize internet-facing HTTP services using affected actix-http versions.
  • Document remediation decisions where beta dependency constraints affect upgrade timing.

Validation and detection

  • Inventory Rust dependencies for actix-http versions before 3.0.0-beta.9.
  • Check lockfiles and SBOMs, not only direct dependencies.
  • Identify services processing HTTP/1 traffic with affected builds.
  • Confirm deployed artifacts match remediated dependency versions.
  • Monitor vendor advisories for additional affected packaging details.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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description · low confidence lookup

Credential and access behavior lookup

The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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cve · low confidence lookup

CVE-2021-38512 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
4Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.